Conference azur::mcc

4560.0. "Multiple Independent MCCs on 1 VMS System" by TRCOA::TIPPER ($DEF/INSTRUCTOR SANDY "Kenneth A.") Wed Feb 17 1993 15:48

    Exactly *which* files in MCC_COMMON, MCC_SPECIFIC and MCC_REPORTS_FILES
    are read-only, and which will/might get created/modified during running
    of MCC v1.2 on VMS?
    
    I must run three or more simultaneous absolutely independant instances
    of DECmcc on the same VAX, so that three sets of students think that
    they have their own, unique, solitary environment, namespace, network,
    etc.
    
    Following the discussion (re ULTRIX implimentation) in notes 4392 and
    4463, and looking at the setup for the MCC_DEMO package, plus a bit of 
    off-line discussion, it seems possible (although a resource pig):
    	- use local MIR for everyone
        - use a separate account for each instance
    	- keep read-only files in the "normal" single places
    	- keep invocation-unique stuff (i.e. read-write data) in the user
    account, and modify the logicals MCC_COMMON etc. to be search lists.
    	- pray
    
    The idea is that each student group walks up to the system as if it has
    *just* completed the MCCEMS022 product installation on an independent
    server, and will run MCC there directing the display to a satellite
    VAXstation (their desktop device).  (*Forget* performance issues -- 
    this is what I am stuck with).  So from here on, site-specific means
    instance-specific or invocation-specific.
                                                       
    What I need to know is, where might site-specific data go, so that I
    don't end up with a single shared copy of conflicting data, or
    alternatively multiple copies of big read-only site-invariant files
    (insufficient disk space to waste)?   The .EXE's at least I can assume
    are site-independent, as with all *.COM files that do not reference
    directories by name (i.e. MCC_LOGICAL_*.COM,MCC_STARTUP_*.COM).
    
    E.g.:
    - Which files contain the local MIR data?  I guess everything that 
    looks like *_MIR.DAT.  
    - Does the MCC_FDICTIONARY.DAT file contain variable stuff?  Does it
    have to be duplicated for each separate instance?  
    - What goes into MCC_SPECIFIC?  Should it be totally site-specific?
    - What about MCC_REPORTS_FILES?  Does anything get written there?
    
    I'm running out of time, and I'm sure that something is going to go
    screwy, but I would appreciate whatever
    hints/suggestions/warnings/experiences you could share.
    
    Sandy Tipper,
    Learning Services,
    Toronto

I think you have got it down.  You may want to read the MM Programmer's 
Guide  (Chap 3 (VMS) or Chap 4 (ULTRIX).  This tells how to set up an 
isolated development environment.  What you are trying to set up is 
essentially the same:

	Private dictionary
	Private MIR (instance and historical attribute)
	Private domains	

...kjn